Many functions of modern devices in automotive, consumer and industrial applications, such as converting electrical energy and driving an electric motor or an electric machine, rely on semiconductor devices. For example, Junction Gate Field-Effect Transistors (JFETs), Metal Oxide Semiconductor Field-Effect Transistors (MOSFETs), and Insulated Gate Bipolar Transistors (IGBTs) are used for various applications including, but not limited to switches in power supplies and power converters.
Many of such semiconductor devices exhibit a vertical structure, e.g., they can be configured to switch currents and/or voltages between a source or an emitter terminal on a front side and a drain or collector terminal on a back side of a semiconductor body. Controlling of the switching can be achieved by means of a gate electrode that is arranged for receiving a control signal from external of the semiconductor device.
For example, the gate electrode of such vertical semiconductor devices is located at least partially inside a trench extending into the semiconductor body. The gate electrode can be insulated from the semiconductor body by an insulating layer such as an oxide layer.